1. Field of the Invention
The present invention relates to a sheet processing apparatus that partially applies a glue on each of sheets to form a glued sheet bundle and an image forming apparatus comprising the sheet processing apparatus.
2. Description of the Related Art
In recent years, a sheet processing apparatus in that causes a pasting process apparatus to apply a glue at predetermined positions on sheets on which an image is recorded by an image forming apparatus and bundle the glued sheets to form a sheet bundle (to bind a book) is proposed.
For example, in a technique disclosed in Japanese Patent Application laid-Open (JP-A) No. 2001-206625, a glue is applied to sheets discharged from an image forming apparatus successively during conveyance, and these sheets are superposed on each other to form (bind up) a glued sheet bundle.
However, in the technique as described in JP-A No. 2001-206625, since a glue is applied to sheets in conveyance successively, a long period of time is required to form a glued sheet bundle. In order to improve the productivity of glued sheets, a conveyance speed of the sheets may be increased to increase an applying speed of the glue accordingly. However, in this case, an application amount of the glue to be applied to the sheets is not stable, and adhesive force between the sheets becomes sparse, so that the quality of the glued sheet bundle may be deteriorated. Since the glue-applied sheets are conveyed, the glue applied to the sheets is dried in the conveyance, and adhesive force between the sheets may be deteriorated. Furthermore, a sheet conveyance portion must be provided to prevent the glue applied to the sheets from adhering to the sheet conveyance portion which conveys the sheets.